A：Could I possibly use your bathroom?
      我能用一下您的洗手间吗?

possibly的反义词

B：Of course.
      当然。

1. 或许；也许
    You use possibly to indicate that you are not sure whether something is true or might happen.

    e.g. Exercise will not only lower blood pressure but possibly protect against heart attacks...
           锻炼不仅会降低血压，而且可能对心脏病有预防效果。
    e.g. They were smartly but casually dressed; possibly students...
           他们衣着时尚，但很休闲，也许是学生。

2. （表示对所见或所闻感到惊讶、困惑或震惊）
    You use possibly to emphasize that you are surprised, puzzled, or shocked by something that you have seen or heard.

    e.g. It was the most unexpected piece of news one could possibly imagine...
           这条新闻最出人意料了，真是让人想象不到。
    e.g. I mean, how could they possibly eat that stuff?...
           我的意思是，他们怎么可能吃那东西呢？

3. 尽量；尽可能地
    You use possibly to emphasize that someone has tried their hardest to do something, or has done it as well as they can.

    e.g. They've done everything they can possibly think of...
           凡是能想到的，他们都去做了。
    e.g. It's one of the nicest feelings you can possibly have.
           这是一种极其美妙的感觉。

4. （加强语气）无论如何也
    You use possibly to emphasize that something definitely cannot happen or definitely cannot be done.

    e.g. No I really can't possibly answer that!
           不，我无论如何也回答不了那个问题。
    e.g. There's nothing more they can possibly do right...
           他们除此之外啥也做不了。